package work.basic;


import java.util.Scanner;

public class Test {
    public static void main(String[] args) {
//        int x;
        int x = new Scanner(System.in).nextInt();
//        x=s.nextInt();
        if (x>=90&&x<=100){
            System.out.println("A");
        }else if (x>=60&&x<90){
            System.out.println("B");
        }else if (x<60){
            System.out.println("c");
        }else {
            System.out.println("请输入有效成绩：");
        }
//        char grade = x >= 90 ? 'A' : x >= 60 ? 'B' : 'C';
//        System.out.println(grade);
    }
}
